Filter unit



g- 19, 1952 J. E. VALENTE 2,607,495

FILTER UNIT Filed May 3, 1946 2 SHEETS-SHEET 1 23 INVENTOR JOHN E. VALENTE ATTORNEYS Aug. 19, 1952 J. E. VALE ZNTE 2,607,495

FILTER UNIT Filed May s, 1946 I 2 SHEETS-SHEET 2 I! 1 a 69 mm lllllll INV ENTOR JOHN E. VALENTE ATTORNEYS.

Patented Aug. 19, 1952 FILTER UNIT ohn E. Valente, Neenah, Wis., assignor to Paper Patents Company, Neenah, Wis., a corporation of Wisconsin Application May 3, 1946, Serial No. 667,190

2v Claims.

The present invention relates to liquid filtering means and is particularly concerned with replaceable filters for use in filtering lubricating oil and. other liquid materials.

It is a well-established fact that the useful life and the operational efficiency of internalcombustion engines can be substantially increased by continuously filtering the oil which is used for lubricating such engines. As a result, various types of oil filters have been proposed and are in use, for this purpose, on automobile and other engines. The usual such filter includes a filtering medium and means for causing the'oil or other liquid to flow therethrough at airate which is consistent with effective filtration. -Since the filtering efficiency of most known filtering materials decreases markedly with use, it is highly desirable to renew the filtering material at regular periods of time, and the filtering material in the better filters is embodied into a replaceable unit or cartridge which can be easily removed and renewed as required.

.While some of the known devices give reasonablysatisfactory results, there are certain, deficiencies and disadvantages inherent therein. Most of these result from undesirable physical and operational characteristics of the filtering materials used. Accordingly, the principal object of the present invention is to provide an improved filtering material especially suited for use in lubricating oil and other fiuid filters. More specifically, it is an object of my invention to provide an improved filtering material which.

can be manufactured at low cost, which can be fabricated into a renewable filter unit more readily and more cheaply than previously known materials, and which, in addition, shall have a very long, useful life.

As will hereinafter appear, these objects of the invention are accomplished by the provision of a filtering material and a filter unit which are of novel construction and design. The filtering material and unit of the invention can be manufactured at high speed, .and at low cost, by the use of known manufacturing methods and existing machinery. Moreover, the filtering material and unit of the invention is capable of wide application and can be readily adapted for various filtering purposes. The various features and advantages of the invention and the structural details of a renewablecartridge type filter embodying-the filtering material and unit of the invention, will be made more apparent in the following description and the accompanying drawings.

- 2 In the drawings, Fig. 1 is a plan view, which is partially cut away and is partially in section, showing a removable filter cartridge embodying a filtering means in accordance with the invention;

Fig. 2 is a sectional'view on the line 2-2 of Fig. 1; r

Fig. 3 is a perspective. view illustrating the filtering means embodied in the filter cartridge of Figs. 1 and 2;

Fig. 4 is a sectional view showing the manner in which the filter cartridge illustrated in Figs. 1 and 2 may be connected into the oil system of a combustion or other type engine;

Fig. 5 is "a diagrammatic view showing the method employed in .themanufacture of one preferred embodiment of a filter element in accordance with the invention; and

Fig. 6. is an enlarged, fragmentary view of a filter element manufactured by the apparatus diagrammatically illustrated in Fig. 5.

The filter cartridge illustrated in Figs. 1 and 2 includes a main supporting shell, or closure, 5, which conveniently comprises a suitable length of a thin walled, hollow, cylindrical tube which is fabricated of oil-proofed cardboard, a molded plastic, or metal. The ends of the tubular shell 5 are closed by a pair of end caps 1 which are rolled onto, or otherwise permanently attached to, the ends of the tube, as shown. Each of the end caps 1 is provided with a plurality of spacedapart dimples 9 formed therein by a pressing operation, and a hole II is provided centrally of each of the dimples 9 in order that the liquid to be filtered may be conducted through the filter cartridge. V 7 g g The filter unit or main filter-body is illustrated at I3 and comprises a right cylindrical section of filtering material which is of such dimensions that it fits snugly within the outer shell 5 of the cartridge when the end caps 1 are in place thereon. To aid in promoting the free flow of liquids through the filter unit l3, a wire screen l5 of fairly heavy mesh, for example about 12 mesh, is disposed'immediately beneath the end cap I at the out-flow end of the filter unit 13, and one or more discs ll, cut from a moderate weight, resin impregnated, multi-ply, cellulosic sheet product are disposed :between the wire screen l5'and the adjacent end surface of the filter unit III. The filter discs ll have the function of removing any extremely fine particles which may be suspended in the oil being filtered. Desirably, the discs I! ar made from a multiply sheet product which comprises a plurality of superposed plies of thin, creped, cellulosic tissue, the individual fibres of which are loaded with a thermoset resin, which is of such nature and is present in suflicient amounts to coat and prevent disintegration of the sheet fibres by action of the liquid being filtered, or by some contaminating material which may be contained in that liquid.

For best results, the liquid being filtered should fiow through the filter unit l3 before reaching the filter discs 11, i. e. the liquid should fiow into the bottom and out of the top of the structure illustrated in Fig.2. This assures the removal of any very fine particles which may be suspended in the liquid being filtered, and which may pass through the main filter unit l3, and it also accomplishes the removal of any part of the filtering material contained in the filter unit I3 which might have become dislodged. During use, it is intended that the entire replaceable, filter cartridge shall be contained within a Suitable holder wh c sv provided with mea s 4 handling the product, it is desirable that a Wrap of paper, such as is illustrated at t! in the drawings shall be placed about the gathered together wadding sheets. As an alternative construction, the outer surface of the rope-like product may be sprayed with adhesive, or a starch, or a resin, which will harden to provide a confining layer; a fabric braid can also be usedif desired. The filter units are made by cutting oil suitable sections of the rope-like product, the length of the sections being determined by the particular requirements of the resulting filter.

One particularly satisfactory method for forming the filter unit. lI-l' is diagrammatically illusbe drawn from the rolls and brought together in for connecting the filter into the oil line, or other 7 liquid filtrate, circuit. One exemplar arrangement of this. type is shown in Fig. 4. The illustrated device includes a hollow, cup shaped, cylindrical, cartridge holder l9 which is open at the top and which is provided with a connection '2! at the bottom for connecting the filter cartridge into an oil line, or the like, as indicated at 23.. The upper end of the filter holder I9. is adapted to be closed by a suitable cover which is provided with a similar central connection 27 for completing the connection to the other end 29.. of the. oil or other filtrate line. .The cover 25 and the holder I9 are provided with cooperating flanges 3 adapted to. be held together by cap screw 33, or the like, in conventional manner. To. assure that all of the liquid whichis pumped or otherwise introduced into the holder shall pass through the filter cartridge, the cooperating parts of the holder are provided with suitable gaskets 35 for engaging theend caps lof the filter cartridge closure.

The filter unit I3 is. possibly the most important part of the present invention; it constitutes a section or length of a rope-like member which is made bygathering together and compressing a plurality ofsimilarl-yarranged, superposed sheets of thin, transversely creped, cellulosic tissue or wadding the resultant product being generally similar 'to the product illustrated and described in the Sackner Patent 1,821,582, which was issued on September 1, 1931. The constituent sheets which make up the rope-like product from which the filter unit i3 is made are drawn through a gathering die orother forming means wherein the sheets are gathered together in irregular convolutions and are compressed in such manner that the creping in these sheets will extend substantially at right angles to the longitudinal axis of the finished product.

Liquid flow through the gathered together sheets takes place through flow passageways which extend longitudinally of the filter unit; The flow paths through the filter unit are thus edgewise of the unit and between the constituent sheets, and generally at right angles to the creping therein. Edges of the constituent sheets are indicated at 31 in Figs. 3 and 6 and the creping lines are indicated at 39 in that figure. Conveniently the rope-like product from which'the filter unit is made is cylindrical in form, as illustrated, and in order to. confine the compressed cellulosic sheets to dimensions and tofacilitate superposed relation as, illustrated at 46. The reping'lineis or crepes 3.9... n each. Q he Pil of each of the multi-ply- Sheets 4,4. are disposed substantially normal, to the line of; movement of; the she ts. e mbined mum-my sheet 6 are fed into. a gatherin ie, or QQ Q idating runnel t5, wherein the sheets are. mechanically compressed and formed into a rope-like member which has a circular cross section. V

The consolidating funnel-4,5,, into which the multi-ply sheets 44 are. fed, is in the form of a hollow, truncated cone having its enlarged end 49, disposed to receive the incoming material. As the sheets of tissue movev downwardly in, the cone, they are gathered, together and compressed along the lines .of' the: crepes-l39r' to. a diameter which is small enough'topass outwardly through the smaller or discharge end, 5!,01v the: consolidating funnel 5.5. At all times during the forming and compressing. operation effected by the passage of the multiaply sheets 4.4. through the consolidating funnel 45, the various portions of the sheets of cellulosic. tissue travel at substantially equal speedsso that thecreping lines maintaintheir positions relative to one another and extend substantially transversely of I the line of travel of the material. J'

The compressed and formed sheets of cellulosic tissue which constitute "theropeelike product il, are maintained in the-compressed state by a' wrapping of iiabric' braid; 53; 'l hi's. is applied to the compressed sheet product by a braiding machinery-5i qiig; 5). The multi ply sheets of cellulosic tissue are drawn from the supply rolls 43, through the consolidating funnel 55, and through the braidingmachine 55- ata substantially constantspeedbymeans of a pair of pull rolls 51. Each ofth'epul-l rolls; 5-! isfabricated from suitable material and is; provided with a concave peripheral groove 5-9 which is proportioned to engagethe rope-like product 47 formed in the consolidating funnel 45. The diameter of the pull rolls 5"l-should-be su'ficient to insure that the rope-like product 41- is not damaged by sharp vbending. The rolls 5? are driven irorn; a suitable semen; power and rotate at a rate ofspeedwhich is propqr-tional to the capacity of the consolidating tunnel-Q After passingthrough the pull ro1ls51; the ropelike product 61 is conducted; through. a spray'of adhesive material as indicated at StihFig; 5. ThQVOllll'IlQ of; adhesive sprayed on thefsurface of the rope-like product 4 1 is re ll-lat'e'dso that the entire; outer surface thereof. is impregnated". After the rope-like product 41- passesthrough the spray, it may be conducted into and through a drying oven 63. Thedrying oven illustrated at 63, includes-a feed .belt or wire 65 for carrying the rope-like product 41 through the oven. The temperaturewithinfthe oven is maintainedsufficiently' high to dry...the adhesive; the dried adhesive impregnated layer is indicated at H in Fig. 6..

After the adhesive has been set or polymerized, the rope-like product 41. is cut into suitable lengths for use in the filter elements l3. The cutting operation may, be accomplished, as illustrated, by a motor driven, high speed rotary knife 61 which is mounted for reciprocating movement upon a suitable table or stand 6-9. In order to increase the efficiency of thesystem the oven conveyor 65 can be of the intermittent type so that the rope-like product 4'! isadvanced through the drying oven 63 in steps. A filter unit I3 then may be cut from the rope-likeproduct 41 each time the conveyor pauses after advancing the material.

Figure 6 shows an enlarged, fragmentary view of the rope-like product 41. In this drawing one of the manypossible configurations of the constituent sheets of cellulosic tissue is illustrated, and for the purposes of clarity the lines which indicatethe boundaries between each of the constituent, multi-ply sheets have been made slightly heavier than the lines which indicate the individual plies of the constituent sheets. However, in a filter unit in accordance with the invention it is substantially impossible to determine the point at which one sheet begins and the other ends.

The oil being filtered passes through the filter unit [3 in a direction parallel to the central axis of that unit. The lines of the creping 39 extend crosswise of each of the sheets and each of the individual plies 31 and, as shown in the drawings, the crepes lie in planes which are substantially perpendicular to the central axis of the filter element. The oil undergoing filtration thus fiows between the layers of multi-ply cellulosic tissue, parallel to the central axis of the unit and crosswise of the creping in the individual sheets. The particular arrangement of the crepes and of the flow passageways embodied in a unit in accordance with the invention, results in an extremely efiicient and practical filter element.

In a particularly satisfactory embodiment of the invention used for oil filtering purposes in connection with the automobile gasoline engines, the basic rope-like product from which the edgewise filter units are cut was fabricated by gathering together seven 10-ply sheets of a thin, creped, cellulosic tissue, each sheet having a width of 42 inches. The final product was circular in cross section, having a diameter of 4 inches, and the filter units comprised 2%; inch sections of the rope-like product. The constituent creped tissue sheets in this embodiment of the invention had a basis weight of about 5.5 pounds for 480 sheets 24 by 36 inches and were made with a crepe ratio of about 2.34. After the gathering and ropeforming operation, the crepe ratio was reduced to about 1.67. The rope product from which the filter units were made had a density of about 10 pounds per cubic foot, the individual filter units weighing approximately 2.2? ounces. The percentage of voids in a unit of this density is within the range of from about 85 to 94 percent.

Measurements indicated that the aggregate flow paths between the constituent sheets of this unit were equivalent to a slot averaging about .004 inch wide and having a length, transversely to .of approximately one gallon per minute with a pressure drop through the edgewise filter unit of approximately ten; pounds per square inch. Since most automotive and other lubricating systems are operated at pressures considerably in excess of this value, the flow rate through the filter is more than adequate.

The. filter discs I]. used in this embodiment of theinvention were of multi-ply construction and comprised 14 plies of thin, creped, cellulosic tissue having a basis weight of about five to seven pounds for 480 sheets 24 by 36 inches and contained about 60 percent by weight of a thermosetting, phenol formaldehyde resin. The resin was uniformly distributed throughout the sheet and served as a protective covering for the sheet fibers. The filter discs H, as previously stated, performed the combined functions of filtering out the very fine particles from the oil passing through the filter and, in addition, they prevented any fibers or other material from being carriedthrough the filtering unit proper intothe oil system.

Although some variation is permissible in the construction of the fabricated rope-like product which is employed in making filter units of the present invention, it appears that the final product should have a unit density of from about 6.0 to 24 pounds per cubic foot. At densities lower than this, there is the tendency to produce channels through the filter, and at densities in excess of the stated amount, the pressure drop through the filter increases rapidly. By far the best results are obtained with densities of the order of from about 7 to 12 pounds per cubic foot in the finished filter units. The creped, cellulosic sheet material used in the fabrication of the product from which the filter units are made should have a basis weight within the range of from about 3 to 7 pounds for 480 sheets 24 by 36 inches, and the crepe ratio of these sheets, as manufactured, should be of the order of from about 2.0 to 4.0. The constituent, creped cellulosic sheets are desirably made of a high quality furnish, such as bleached sulphite pulp, in order to prevent contamination of the material being filtered.

It will be apparent that filtering units of the type disclosed in the foregoing are capable of rather wide application in the filtering art. The unit may or may not be enclosed within a cartridge, and if a cartridge is used, it need not be of any particular type. The utility of the filter appears to be due primarily to the arrangement of plies and creping, which results in the formation of filter passageways which are equivalent to a single, very long passageway of extremely narrow width. The edgevvise arrangement of the constituent creped sheets in the filter unit so as to cause the oreping in the sheets to extend substantially at right angles to the path of liquid fiow through the filter unit is considered a very important feature of the invention. While particularly suitable for filtering lubricating oil or 7 like materials which contain fine suspended solids, the filtering unit of the invention is equally satisfactory for'other' types of liquids.v The features oitheinvention, which are believedto be new, are expressly set-forth in the accompanying c1aim's.

I claim the following: 7 r

1.- A filter unit of the class described comprisinga plurality of superposed sheets of thin, creped cellulosictissue, said sheets having a basis weight within therange of' from about 3 to '7 pounds for- 480 sheets 24 by 36' inchesand a crepe ratio when manufactured, of from about 2.0 to 4.0, the crepe'lines of-said sheets being mutually substantially parallel, said-sheets being disposed in irregular 'convolutions in the direction of said crepe lines; andcompressed .in the direction of said crepe lines "toprovide-a filter body having a unit density within the range offrom about 6.0- to 24 pounds per cubic foot; the axes of Said convolutiens being't'ransvers'e of said crepe lines, adjacent ones of said sheets defining therebetween tortuous flow passageways extending 1ongitudinally through said filter body substantially parallel tothe axes of said convolutions and at substantially right angles to said crepe lines.

2. A filter unit of the class described, comprising a plurality of superposed sheets of thin, ereped cellulosic tissue, said sheets having a basis weight within the range of from 3 to 7 pounds for 480'sheets 2-4hy 36 inches and a crepe ratio, when manufactured, or from about 2.0 to 4.0, the crepe lines of said sheets being-mutually substantially parallel, said sheets being disposed in irregular convolutions in the direction of said crepe lines angles to said crepe lines.

JOHN E. VALENTE.

: anrnanncns CITED The following references areof recordin the file of this patent:

UNITED 'S'l-ATES PATENTS Number" Name Date v 1,729,135 ,Slauso'n -1 Sept. 24,1929 1,821,582 Sackner Sept. 1, 1931 2,048,350 McLean July 31,1936 2,076,935 Burckhalter Apr. 13-, 1937 2,164,702 Davidson 2 1' Ju1y 4, 1939 2,196,821 Arnold Apr. 9, 1940 2,226,313 Ehlers Dec. 16,. 1941 2,292,513 Fourness et. al Aug. 11, 1942 2,347,384 Winslow et al Apr. 25, 1944 2,380,111 Kasten 11 July 10, 1945 2,386,684 Hermanson Oct. 9, 1945 2,387,714 Briggs 1 Oct. 30, 1945 2,388,668 Carter 1 Nov. 13, 1945 2,413,431 Briggs 1 Dec. 31, 1946 2,421,704, Kasten 1 June 3, 1947 2,468,328 Hill Apr. 26, 1949 

